PUSHROD ENGINE WITH MULTIPLE INDEPENDENT LASH ADJUSTERS FOR EACH PUSHROD

US 20080083382A1
Filed: 10/06/2006
Published: 04/10/2008
Est. Priority Date: 10/06/2006
Status: Active Grant

First Claim

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1. A multiple-cylinder internal combustion engine having a camshaft-driven valvetrain with a camshaft disposed within an engine block, the engine including at least two valves operated by a common camshaft lobe, the engine comprising:

a lifter in contact with the common camshaft lobe;

a single pushrod associated with each lifter;

a follower engaging the single pushrod and reciprocating within a corresponding bore in response thereto, the follower engaging at least two rocker arms, each rocker arm actuating a different one of the at least two valves.

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Abstract

A multiple-cylinder internal combustion engine having a camshaft-driven valvetrain with a camshaft disposed within an engine block includes at least two intake and/or exhaust valves with multiple valves operated by a common lifter and pushrod that engages a follower having multiple independent lash adjusters coupled to associated rocker arms. The lifter contacts the common camshaft lobe and a corresponding pushrod that engages a reciprocating bucket follower with a compliant coupling to corresponding rocker arms.

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20 Claims

1. A multiple-cylinder internal combustion engine having a camshaft-driven valvetrain with a camshaft disposed within an engine block, the engine including at least two valves operated by a common camshaft lobe, the engine comprising:
- a lifter in contact with the common camshaft lobe;
  
  a single pushrod associated with each lifter;
  
  a follower engaging the single pushrod and reciprocating within a corresponding bore in response thereto, the follower engaging at least two rocker arms, each rocker arm actuating a different one of the at least two valves.
- View Dependent Claims (2, 3, 4, 5, 6, 7)
- - 2. The engine of claim 1 wherein the follower comprises:
    - a bucket follower having at least two independent lash adjusters associated with each pushrod, each lash adjuster engaging a corresponding rocker arm.
  - 3. The engine of claim 2 wherein the follower comprises:
    - at least two independent hydraulic lash adjustment mechanisms, each lash adjustment mechanism having a compliant coupling engaging an associated rocker arm.
  - 4. The engine of claim 1 wherein the follower comprises:
    - at least two independent hydraulic lash adjustment mechanisms and wherein at least one of the adjustment mechanisms and the rocker arms includes a pivotable surface.
  - 5. The engine of claim 1 wherein the follower comprises:
    - a housing;
      
      a first sleeve disposed within a first bore in the housing and having a closed end and an open end;
      
      a first plunger disposed within the first sleeve and defining a first high-pressure chamber between the closed end and the first plunger;
      
      a first check valve disposed between the first plunger and the first sleeve for controlling flow of hydraulic fluid from the first plunger into the first high-pressure chamber, the hydraulic fluid in the high-pressure chamber along with the plunger spring operating to remove lash associated with the push rod, a first rocker arm, and a first valve;
      
      a second sleeve disposed within a second bore in the housing and having a closed end and an open end;
      
      a second plunger disposed within the second sleeve and defining a second high-pressure chamber between the closed end and the second plunger; and
      
      a second check valve disposed between the second plunger and the second sleeve for controlling flow of hydraulic fluid from the second plunger into the second high-pressure chamber, the hydraulic fluid in the second high-pressure chamber along with the plunger spring operating to remove lash associated with the push rod, a second rocker arm, and a second valve.
  - 6. The engine of claim 1 wherein the follower reciprocates within a bore at least partially disposed within a cylinder head.
  - 7. The engine of claim 1 wherein the follower reciprocates within a bore disposed within a fulcrum mounted to a cylinder head.

8. A valvetrain for a multiple-cylinder internal combustion engine having a camshaft disposed within an engine block for operating two valves from a single camshaft lobe, the valvetrain comprising:
- a lifter having a roller for contacting the camshaft lobe and reciprocating within the engine block in response thereto;
  
  a pushrod engaging the lifter;
  
  a bucket follower engaging the pushrod and reciprocating within a corresponding bore in response thereto, the bucket follower including first and second hydraulic lash adjusters; and
  
  first and second rocker arms each associated with a respective one of the first and second hydraulic lash adjusters and a respective one of the two valves.
- View Dependent Claims (9, 10, 11, 12, 13)
- - 9. The valvetrain of claim 8 wherein the two valves are intake valves associated with one of the cylinders.
  - 10. The valvetrain of claim 8 wherein the two valves are exhaust valves associated with one of the cylinders.
  - 11. The valvetrain of claim 8 wherein the bucket follower reciprocates within a bore at least partially disposed within a cylinder head.
  - 12. The valvetrain of claim 8 wherein the first and second lash adjusters comprise hydraulic lash adjusters having a high-pressure chamber containing a variable amount of hydraulic fluid to remove lash from a corresponding pushrod and respective rocker arm and valve assembly.
  - 13. The valvetrain of claim 8 further comprising:
    - a fulcrum associated with each of the first and second rocker arms, the fulcrum having a bore adapted to receive the bucket follower.

14. A method for actuating at least two gas exchange valves associated with a single cylinder in a multiple-cylinder internal combustion engine having a camshaft disposed within an engine block, the method comprising:
- actuating the at least two gas exchange valves substantially simultaneously using a single lifter and pushrod associated with a follower having at least two corresponding independent lash adjustment mechanisms that engage corresponding rocker arms to actuate the gas exchange valves.
- View Dependent Claims (15, 16, 17, 18, 19, 20)
- - 15. The method of claim 14 wherein the follower reciprocates within a bore in a cylinder head.
  - 16. The method of claim 14 wherein the internal combustion engine includes four valves per cylinder and wherein the step of actuating comprises actuating two intake valves.
  - 17. The method of claim 14 wherein the follower includes at least two independent hydraulic lash adjusters.
  - 18. The method of claim 14 wherein the rocker arms are mounted on a fulcrum that includes a bore and wherein the follower reciprocates within the bore in the fulcrum.
  - 19. The method of claim 14 wherein the step of actuating comprises actuating a lifter having a single pushrod coupled to a bucket follower having at least two independent hydraulic lash adjusters coupled to corresponding rocker arms to actuate the gas exchange valves.
  - 20. The method of claim 19 wherein either the lash adjusters or the rocker arms include a pivotable coupling.

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Current Assignee
Ford Global Technologies, LLC (Ford Motor Company)
Original Assignee
Ford Global Technologies, LLC (Ford Motor Company)
Inventors
Diggs, Matthew

Granted Patent

US 7,424,876 B2
Time in Patent Office

Days
Field of Search
US Class Current

123/90.4
CPC Class Codes

F01L 1/14   Tappets hydraulic tappets f...

F01L 1/18   Rocking arms or levers

F01L 1/181   Centre pivot rocking arms

F01L 1/2422   by means or a hydraulic adj...

F01L 1/255   between cam and rocker arm

F01L 1/26   characterised by the provis...

F01L 2305/00   Valve arrangements comprisi...

Y10T 74/2107   Follower

PUSHROD ENGINE WITH MULTIPLE INDEPENDENT LASH ADJUSTERS FOR EACH PUSHROD

First Claim

2 Assignments

0 Petitions

Accused Products

Abstract

16 Citations

20 Claims

Specification

Solutions

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PUSHROD ENGINE WITH MULTIPLE INDEPENDENT LASH ADJUSTERS FOR EACH PUSHROD

First Claim

2 Assignments

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Subscription Required

0 Petitions

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Accused Products

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Abstract

16 Citations

20 Claims

Specification

Subscription Required

Solutions

Use Cases

Quick Links